Atlantic Street Bridge Project
Utilizing Accelerated Bridge Construction for
Metro North Bridge Replacement

What does Accelerated Bridge Construction mean? Accelerated Bridge Construction (ABC) is an innovative bridge building technique that is being utilized for the Atlantic Street Bridge project to replace the Metro North Bridge over Atlantic Street. Typically, to build and replace a bridge of this size while not causing major disruptions to train service, years would be needed to complete the project as the work would slowly progress track by track from foundation to final track completion. Access beneath the bridge would be closed for the entire duration of the project with work going on constantly overhead. With ABC techniques, these disruptions are now minimized to a matter of months and in some cases days. With safety and cost efficiencies a top priority, ABC methodologies used in planning, design, construction materials and methods, considerably reduce onsite construction time associated with bridge construction, replacement or rehabilitation.

The ABC techniques reduce traffic impacts, on-site construction time, environmental impacts and weather-related delays. Work zone safety for the traveling public and construction personnel as the safety of the traveling public and transportation network operations, patterns, flow and efficiencies are directly impacted by onsite construction related activities.

For the replacement of the Atlantic Street Bridge, long term closures of the underpass are only required to widen and lower the roadway. A four-month closure of the underpass is necessary to install the center pier foundations required by the longer span and a two-month closure is required to lower Atlantic Street after the bridge is installed. The vast majority of the bridge construction will occur without disruption to street traffic or regular train service.

Click here to view an ABC project successfully completed on I-84 in Southington, CT.
Work begins June 2018 to prepare the site to accept the new structure scheduled to be rolled in over a 9 day period over the 4th of July holiday week in 2019. Rail service over the bridge will be reduced to two running tracks during the roll-in and reopened to full rail service by the end of that week. Additional work will widen and lower Atlantic Street, which will reopen to traffic at the beginning of September 2019. The remainder of the project will upgrade overhead catenary power systems, add a dedicated local service track along with a new passenger platform and stairs. This work is expected to be completed by November 2020.